Master AI Engineering,
System Design & DSA With Interactive Simulators
Build & visualize Data Structures, Algorithms, Neural Networks, Self-Attention, and RAG in real-time. Code high-scale distributed systems, master DSA patterns, and ace your AI, DSA & System Design interviews.
1public int binarySearch(int[] arr, int target) { 2 int low = 0, high = arr.length - 1; 3 while (low <= high) { 4 int mid = (low + high) / 2; 5 if (arr[mid] == target) return mid; 6 if (arr[mid] < target) low = mid + 1; 7 else high = mid - 1; 8 } 9 return -1; 10}
Break into leading tech companies
Experience Simple & Visual Simulators
Our interactive playgrounds make complex data structures, algorithms, and system architectures easy to grasp in seconds.
Visual Sorting Algorithms
Watch how computer sorting algorithms order elements step-by-step. Bubble Sort repeatedly steps through the list, compares adjacent elements, and swaps them if they are in the wrong order.
- check_circle Live adjacent value comparison tracking
- check_circle Color-coded index pointers (j, j+1)
- check_circle Simple, clean code-trace walkthrough
for (int i = 0; i < n-1; i++) for (int j = 0; j < n-i-1; j++) if (arr[j] > arr[j+1]) { // Swap arr[j] and arr[j+1] int temp = arr[j]; arr[j] = arr[j+1]; arr[j+1] = temp; }
System Design: Load Balancer
Master high-scale system designs. Learn how load balancers route user requests Round Robin style, detect server failures, and automatically failover traffic to remaining healthy nodes.
- check_circle Live round-robin request distribution
- check_circle Node partition & crash simulation
- check_circle Dynamic active traffic re-routing
LRU Cache Eviction Simulator
Visualize how caching strategies save query time. Watch memory fill up, monitor cache Hits and Misses, and see how the Least Recently Used (LRU) element is evicted when memory capacity is full.
- check_circle Live cache memory representation
- check_circle Hit / Miss and Eviction status highlights
- check_circle Head/Tail pointer indicators
Everything you need to ace your coding, system design, and AI interviews.
We've built a highly optimized, feature-rich learning ecosystem that turns complex algorithms, system architectures, object-oriented designs, and AI models into clear, tangible visualizations.
AI & Machine Learning Mastery
Visualize neural networks, A* pathfinding, K-Means clustering, self-attention, and RAG pipelines in real-time to master AI engineering and pass modern technical interviews.
Real-Time Code Tracing
Step through optimal solutions in Java, Python, and C++ line-by-line. Watch the highlighted execution flow in perfect sync with live local variables and custom debugger inputs.
Interactive Sandboxes & Simulators
Simulate live HTTP traffic, load balancers, database replication, and consensus protocols in real-time, alongside complex data structures like Trees and Graphs.
600+ Curated Problems
Mastering data structures, algorithms, system design, and AI is essential. We've hand-picked over 600 of the most frequently asked FAANG coding and design problems to build your conceptual understanding.
Object-Oriented Design (OOD)
Ace your OOD rounds by designing parking lots, movie booking systems, and ATMs. Visualize class relationships, design patterns, and UML diagrams step-by-step.
Verified Achievement Certificate
Earn a verified Certificate of Achievement upon successfully completing our learning paths, showcasing your expertise in DSA, System Design, and AI on your resume or LinkedIn.
Structured Learning Roadmaps
Follow highly structured, day-wise learning paths or leverage our AI-powered roadmap generator to achieve technical mastery in a deterministic, well-paced journey.
Interactive Mastery Quizzes
Validate your understanding by taking bite-sized challenges for every problem. Test your knowledge in DSA, System Design, Java, and AI to earn XP and level up.
Gamified Progress Tracking
Sign in with Google to save your progress, bookmark challenging problems, track your topic-wise mastery rings, and climb the global developer leaderboard.
AI Mock Interviews
Ace your behavioral and coding phone screens. Get instant, voice-activated feedback, transcript analysis, and custom scorecards powered by advanced AI models.
27 Core Coding Patterns
Stop memorizing solutions. Master the 27 underlying visual patterns (Sliding Window, Two Pointers, K-way Merge) that solve over 95% of top-tier coding questions.
EM & Behavioral Simulator
Scale your leadership and systems. Navigate team design conflict, system sharding trade-offs, and project planning in real-time roleplay simulations.
AI & Machine Learning
Neural networks, generative AI, deep learning mechanics, and classical ML math
Learning Path
AI Mastery Course
Follow our structured curriculum to master neural networks, large language models, agents, and evaluations.
AI Playground Hub
Explore the full directory of interactive visualizers, sandboxes, and AI tuning arenas.
Generative AI & LLMs
Diffusion Model
Visualize step-by-step image generation and noise addition/removal in latent spaces.
Self-Attention Matrix
Visualize how transformers calculate token relationships and build attention maps.
LoRA Fine-Tuning
Simulate parameter-efficient fine-tuning with rank selection, weight updates, and VRAM calculations.
RLHF Alignment
Step through Reinforcement Learning from Human Feedback: reward models, PPO updates, and alignment.
RAG Pipeline Flow
Visualize Retrieval-Augmented Generation from PDF chunking to vector database retrieval.
ReAct Agent
Trace how LLMs reason, search, and act in loops to solve multi-step external tool tasks.
Deep Learning Mechanics
Neural Network Playground
Build, train, and visualize a neural network live in your browser. Tune layers, activations, and learning rates.
3D Optimizer Race
Compare SGD, Momentum, RMSprop, and Adam as they descend loss landscapes in 3D.
Dropout Playground
Visualize co-adaptation prevention and regularization by randomly deactivating network nodes.
AI Tuning Arena
Experiment with learning rate schedules, batch sizes, weight initialization, and check results.
Classical ML & Math
KNN Classifier
Plot dataset points and visualize K-Nearest Neighbors decision boundaries and distance metrics.
Regression & GD
Visualize linear/polynomial regression fitting and gradient descent steps on error surfaces.
Decision Tree Builder
Step-by-step split selection using Entropy/Gini Impurity to construct a classification decision tree.
Minimax Game Tree
Explore the game tree, alpha-beta pruning, and decision values of the Minimax adversarial search algorithm.
Calculus Derivative Slider
Interact with slopes, tangent lines, and limits to build an intuitive understanding of differentiation.
Eigenvalue Visualizer
Visualize matrix transformations, eigenvectors, eigenvalues, and coordinate rotations.
DSA & Coding
Study guides, data structures, algorithms, and visualization tools
Study Guide
Dashboard
Go to your learning dashboard to track your progress and stats.
Interactive Academy
Step-by-step interactive lessons, quizzes, and live code execution traces.
DSA Arcade
Gamify your DSA preparation with coding arcade challenges and timing runs.
DSA Library
Practice and visualize execution flows for 500+ curated LeetCode problems.
Coding Patterns
Master the 15+ patterns (Sliding Window, Two Pointers) that solve 90% of LeetCode.
Big-O Cheat Sheet
Time and space complexities cheat sheet with interactive charts.
Algorithm Odyssey
Embark on a gamified journey to learn algorithms and structures.
Efficiency Race
Compare running times of different algorithms live inside your browser.
Visual Lab
Experiment with raw data structures and custom test-bed configurations.
Educational Blog
Read articles and blog posts about software engineering and computer science.
Data Structures
Linked List Reverser
Visualize step-by-step pointer manipulations to reverse a singly linked list.
Tree Merger Sandbox
Visualize merging two binary trees by traversing and combining overlapping nodes.
Linked List / Stack / Queue
Visualize singly linked lists, stacks, queues, and double-ended queues.
BST & AVL Tree
Visualize Binary Search Trees and self-balancing AVL tree rotation steps.
Red-Black Tree
Visualize red-black tree insertion, deletion, and rotation balancing.
B-Tree (2-3 Tree)
Visualize B-Tree insertion, deletion, split, and merge operations.
Binary Heap
Visualize heapify, insertion, and deletion steps in binary heaps.
Hash Table
Visualize closed addressing chaining and open addressing probing methods.
Segment Tree
Visualize segment tree creation, range query, and point updates.
Fenwick Tree (BIT)
Visualize binary indexed tree updates and prefix sum calculations.
Trie (Prefix Tree)
Visualize prefix tree insertion, search, and autocomplete operations.
Skip List
Visualize search, insertion, and deletion in a probabilistic skip list.
Huffman Coding Tree
Visualize greedy Huffman encoding, building the frequency tree, and prefix codes.
Self-Balancing Trees
Compare rotations and heights of AVL, Red-Black, and Splay Trees.
Quadtree Sandbox
Visualize spatial partitioning and 2D collision detection with Quadtrees.
K-D Tree Sandbox
Visualize multi-dimensional search and nearest neighbor queries on K-D Trees.
Cartesian Tree & Treap
Visualize the binary search tree and heap hybrid (Treap) operations.
Algorithms
Two Sum Sandbox
Visualize the two pointer and hash map approach to solve the classic Two Sum problem.
Sorting Algorithms
Visualize Bubble, Selection, Insertion, Merge, Quick, and Heap sort algorithms.
Graph Traversal (DFS/BFS)
Explore BFS and DFS search patterns node-by-node across visual graphs.
Minimum Spanning Tree
Visualize Prim's and Kruskal's algorithms for MST finding.
Shortest Paths (SSSP)
Visualize Dijkstra's and Bellman-Ford shortest path algorithms.
Network Flow (Max Flow)
Visualize Ford-Fulkerson and Edmonds-Karp maximum flow algorithms.
Traveling Salesperson
Visualize TSP solving with dynamic programming, backtracking, and heuristics.
KMP String Matching
Visualize Knuth-Morris-Pratt substring search and prefix function array.
Aho-Corasick Multi-Pattern
Visualize Aho-Corasick prefix/suffix link trie for multi-pattern search.
Strongly Connected Components
Visualize Tarjan's and Kosaraju's algorithms for finding graph SCCs.
Convex Hull
Visualize Graham Scan and Monotone Chain algorithms for 2D Convex Hull.
Floyd's Cycle Finding
Visualize Floyd's tortoise and hare cycle detection in linked lists.
Floyd-Warshall Algorithm
Visualize the dynamic programming approach for all-pairs shortest paths.
Pathfinding & Maze Sandbox
Create custom mazes and watch A*, Dijkstra, and Greedy Best-First search paths.
Dynamic Programming Quiz
Test your skills on classic DP problems: LCS, LIS, Knapsack, and Edit Distance.
String Slot Machine
An interactive slot machine simulator for regex and string matching concepts.
System Design
Fundamentals, replication & consensus, and real-world system designs
Fundamentals
Circular Array Modulo Pointer
Visualize how a circular array (ring buffer) pointer wrapping works dynamically using the modulo operator.
Parking Lot OOD
Simulate parking lot object-oriented design and spot allocation strategies based on vehicle size constraints.
OOD Deck of Cards
Visualize standard deck model design (Encapsulation, Enums, Aggregation) and test it inside a Blackjack game loop.
API Design Studio
Master RESTful best practices, rate limiting, and Stripe/Twitter API design with interactive consoles.
gRPC vs REST vs GraphQL
Compare communication protocols: JSON payloads, protobuf serialization, and queries.
API Auth Simulator
Learn how modern and legacy APIs handle authentication: JWT, OAuth 2.0 with PKCE, Session Cookies, and mTLS.
Cybersecurity Simulator
Master web security: interact with SQL Injection, XSS, CSRF, IDOR, and Command Injection labs.
Asynchronism & Backpressure
Explore queue management, rate limiting, and backpressure policies like DropLatest, DropOldest, Throttle, and PushBack.
Frontend System Design
Learn how to scale client-side performance, assets delivery, and state synchronization.
Stress-Test Playground
Simulate virtual users hammering your service and observe degradation curves.
Architecture Sandbox
Simulate live HTTP traffic, load balancers, caching, and database replication.
12-Factor Microservices
Master the 12-factor methodology for building SaaS, cloud-native, and twelve-factor microservices.
Distributed Basics
Learn characteristics, availability vs consistency, and networks in distributed environments.
Load Balancing
Visualize round-robin, least-connections, and IP hashing load balancing algorithms.
Caching Sandbox
Visualize cache eviction policies like LRU, LFU, and FIFO under load.
Data Partitioning
Learn sharding techniques, range-based, hash-based, and directory partitioning.
Consistent Hashing
Visualize hashing rings, node joining/leaving, and virtual nodes.
Database Indexes
Visualize how B-Tree indexes, hash indexes, and scans work under-the-hood.
DB Scaling & Partitioning
Compare database Federation, Sharding (key/range-based), and Denormalization. Visualize query amplification.
Reverse Proxies
Learn reverse proxies, forwarding, SSL termination, and caching basics.
Network Protocols
Compare TCP, UDP, HTTP/2, and WebSockets packet flows visually.
DNS Simulator
Trace DNS recursion from root, TLD, to authoritative servers packet-by-packet.
IP Address Simulator
Master IP subnetting, CIDR blocks, and IPv4 vs IPv6 headers.
HTTP Status Codes
Interactive match simulator for 1xx, 2xx, 3xx, 4xx, and 5xx status codes.
Transaction Isolation
Simulate read phenomena: dirty reads, non-repeatable reads, phantom reads.
Latency Timeline
Scale nanoseconds to human time to build an intuitive grasp of cache, memory, disk, and network speeds.
Distributed Chat LLD
Visualize WebSocket gateway connections, presence store routing, pub/sub broker delivery, and persistent DB storage.
Replication & Consensus
Redundancy & Replication
Learn active-passive, active-active, and multi-leader replication setups.
SQL vs NoSQL DBs
Compare relational schemas, document stores, key-value stores, and graph DBs.
Quorum Consensus
Simulate replica read/write quorums and understand strong vs eventual consistency.
Leader Election
Visualize leader selection and failovers when nodes drop off.
Heartbeat Checks
Watch system check-ins and failure detection thresholds.
Service Discovery Registry
Observe client registration, periodic keep-alive heartbeats, health state transitions, and automatic node pruning.
Checksum Integrity
Learn how hash checks detect packet corruption and data tampering.
Gossip Protocol
Watch peer-to-peer data propagation and anti-entropy synchronization.
Raft Consensus
Interactive visualization of Raft leader election, log replication, and safety guarantees.
Rate Limiting
Visualize token bucket, leaky bucket, and sliding window rate limiting.
CAP Theorem
Simulate network partitions and trade off availability vs consistency.
PACELC Theorem
Understand latency vs consistency when there are no partitions.
Bloom Filters
Visualize probabilistic membership checks using multiple hash functions.
Web Communication
Compare polling, long-polling, WebSockets, and Server-Sent Events.
Real-World Designs
TinyURL Shortener
Design a high-scale URL shortening service: hashing, custom aliases, redirection.
Instagram Design
Design a photo-sharing feed: timeline compilation, push vs pull models, uploads.
Twitter Feed Design
Design Twitter timelines: fanout-on-write, home timelines, and celebrity traffic.
YouTube Streaming
Design video sharing: CDN distribution, adaptive bitrate streaming, encoding.
Distributed Queue
Design Kafka/RabbitMQ style queues: partitions, offset management, consumer groups.
Collaborative Doc
Design real-time editors (Google Docs) using Operational Transformation & CRDTs.
Dropbox Design
Design file sync & storage: block-level sync, metadata DB, and chunk servers.
Uber Design
Design ride-hailing: geospatial indexing (S2/H3), driver matching, location updates.
Ticketmaster Design
Design booking systems: lock mechanisms, caching, flash sale traffic surges.
Messenger Design
Design chat applications: push notifications, websocket connections, message store.
Web Crawler
Design distributed crawlers: URL frontier, politeness, content deduplication.
Google Maps
Design mapping & routing: tile rendering, Dijkstra on road networks, ETA calculation.
Payment System
Design high-reliability payments: idempotency keys, dual-entry ledger, reconciliation.
Discord Design
Design chat/voice architecture: gateway service, pub/sub, audio routing.
Interactive Simulators
Simulator labs and featured engineering sandbox simulators
Simulator Labs
Simulators Hub
Interactive software engineering and system design simulation sandbox.
Code Smell Hunter
Find, identify, and refactor bad code smells in interactive source files.
CI/CD Rollout Lab
Simulate blue-green switchovers, canary traffic routing, and auto-rollbacks.
Visual Lab (DSA)
Experiment with raw data structures and custom test-bed configurations.
Efficiency Race
Compare running times of different algorithms live inside your browser.
Featured Simulators
Engineering Manager
Handle team conflicts, project deadlines, and make critical leadership decisions.
Cybersecurity Attack
Simulate attacks like SQL injection, XSS, and command injections in a sandbox.
Raft Consensus
Interactive visualization of Raft leader election, log replication, and safety guarantees.
HA Failover Clusters
Interact with active-passive virtual IP failovers, replication lag, and active-active split-brain network partitions.
Cron Job Scheduler
Master cron expression syntax. Visualize future execution schedules.
Semantic Versioning
Master semantic versioning increments and dependency range resolution.
Mastery Courses
Programming & databases, developer essentials, and advanced topics
Programming & DBs
Java Mastery
Master advanced core Java, JVM internals, garbage collection, and concurrency.
Python Mastery
Master advanced Python, generators, decorators, memory management, and async.
SQL Mastery
Master advanced relational databases, query planning, indexing, and joins.
React Mastery
Master concurrent React, fibers, custom hooks, and state reconciliation.
Angular Mastery
Master Angular signals, zone-less execution, custom directives, and routing.
JavaScript Mastery
Learn prototype inheritance, event loop, closures, and ES6+ under-the-hood.
Dev Essentials
Git Mastery
Deep dive into Git internals: trees, blobs, commits, rebasing, and cherry-picking.
Command Line (CLI)
Master bash scripting, pipes, redirections, grep, awk, and sed tools.
HTTP & Networking
Understand HTTP/1.1 vs HTTP/2 vs HTTP/3, headers, caching, and CORS.
Advanced Topics
AI & Agentic AI
Follow our structured curriculum to master neural networks, large language models, agents, and evaluations.
Security Mastery
Learn hashing vs encryption, SSL handshakes, JWT security, and CSRF protection.
CSS Mastery
Master CSS specificity, grid, flexbox, BEM, and advanced animations.
Career Roadmaps
Developer tracks, architect, and engineering management roadmaps
Developer Tracks
Roadmaps Hub
Structured study guides and professional track learning paths.
Frontend Developer
Structured path to learn HTML, CSS, JavaScript, frameworks, and performance.
Backend Developer
Structured path to learn databases, APIs, scaling, caching, and system design.
Fullstack Developer
Comprehensive roadmap from UI design to scalable backends and databases.
DevOps Engineer
Learn pipelines, Docker, Kubernetes, infrastructure-as-code, and cloud.
Architect & Management
Software Architect
Master architectural patterns, enterprise scaling, integration, and DDD.
AI Engineer
Structured study plan to master neural nets, LLMs, fine-tuning, and RAG.
Data Engineer
Learn data warehouses, ETL pipelines, Spark, Hadoop, and big data structures.
Android Developer
Structured plan to master Kotlin, Jetpack Compose, state, and mobile architecture.
Product Manager
Learn metrics, design thinking, scrum, roadmapping, and user stories.
Engineering Manager
Structured path to master leadership, engineering processes, and operations.
Interview Prep
Prep guides, core courses, and language or database Q&A resources
Prep Guides
Learning Roadmap
Follow our structured CS algorithm journey to master core topics.
AI Mock Interview
Practice mock coding and system design interviews with our AI agents.
Resume Tips
Score your resume, check keywords, and optimize for ATS scanner platforms.
Behavioral Prep
Learn behavioral strategies, STAR framework templates, and mock scenarios.
EM Interview Simulator
Handle leadership scenarios, team friction, and scaling decisions live.
Interview Playbook
Comprehensive checklist and blueprints for cracking tech interviews.
Flashcards
Study DSA and system design concepts with interactive flashcards.
Core Courses
DSA Prep Course
Interactive, visualization-based prep course covering arrays to graphs.
System Design Prep
Master fundamental distributed characteristics, scaling, and databases.
OOD Prep Course
Master object-oriented design patterns and UML structural diagrams.
Language & DB Q&As
Java Q&As & Scenarios
Master core Java interview questions, GC, JVM internals, and concurrency.
Python Q&As & Scenarios
Master core Python interview questions, decorators, generators, and memory.
SQL Q&As & Scenarios
Master relational DB interview questions, query planner, indices, and joins.
React Q&As & Scenarios
Master React interview questions, virtual DOM, reconciliation, and hooks.
Angular Q&As & Scenarios
Master Angular interview questions, change detection, routing, and modules.
Certification Exams
Cloud & DevOps, AI & ML, and security, agile, or PM mock certifications
Cloud & DevOps
AWS Solutions Architect - Assoc.
Full mock exam and review for AWS Certified Solutions Architect - Associate.
AWS Solutions Architect - Prof.
Advanced level mock exam for AWS Certified Solutions Architect - Professional.
AWS Developer - Associate
Mock exam for AWS Certified Developer - Associate: serverless, deployments.
Azure Administrator (AZ-104)
Mock exam for Microsoft Azure Administrator AZ-104: storage, networking.
Azure Solutions Architect (AZ-305)
Mock exam for Microsoft Azure Solutions Architect AZ-305: architecture design.
Terraform Associate
Mock exam for HashiCorp Certified: Terraform Associate: IaC workflows.
Kubernetes CKA
Mock exam questions mirroring CKA practical topics: config, storage.
Kubernetes CKAD
Mock exam questions mirroring CKAD: application creation and configs.
AI & Machine Learning
Azure AI Engineer (AI-102)
Mock exam for Designing and Implementing a Microsoft Azure AI Solution.
Agentic AI Solutions Architect
Mock exam for Agentic AI solutions design, workflow loops, and integrations.
Security, Agile & PM
CISSP Security Professional
Mock exam for Certified Information Systems Security Professional.
CompTIA Security+
Mock exam for CompTIA Security+: core security protocols, infrastructure.
Certified Ethical Hacker (CEH)
Mock exam covering penetration testing, vulnerabilities, and malware.
Cisco CCNA Networking
Mock exam for Cisco Certified Network Associate: IP services, routing.
Project Management Prof. (PMP)
Mock exam for Project Management Professional: agile, waterfall processes.
Professional Scrum Master (PSM I)
Mock exam for Professional Scrum Master I: values, rules, frameworks.
Role-Based Interview Prep
Master role-wise interview questions and interactive quizzes for high-paying roles
Prep Tracks
AI Engineer
Master neural networks, LLM fine-tuning, RAG, and agentic AI architectures.
Software Engineer Backend
Master systems design, database indexing, sharding, caching, and APIs.
SRE
Master site reliability engineering, observability, post-mortems, and distributed systems.
Forward Deployed Engineer
Master client integration engineering, solution design, troubleshooting, and enterprise architecture.
Data Engineer
Master ETL pipelines, MapReduce, sharding, stream processing, and big data.
Frontend Engineer
Master JavaScript, CSS, HTML, DOM, web performance, and modern frameworks.
Cybersecurity Engineer
Master security concepts, threat modeling, network security, penetration testing, and cryptography.
Engineering Manager
Master technical leadership, team operations, deadlines, and scaling decisions.
Cloud Infrastructure Engineer
Master cloud platforms, virtual networks, IAM, infrastructure-as-code, and provisioning.
Technical Product Manager
Master technical roadmap designs, system constraints, user requirements, and agile delivery.
What Engineers Say About AlgoSteps
Real feedback from developers who accelerated their learning and aced their interviews.
"The step-by-step execution tree for backtracking solved my confusion in minutes. I could see the state of the recursion stack and how values changed in real-time."
"I was struggling with system design concepts like consistent hashing and load balancing. The interactive playgrounds let me simulate server failures and load spikes. Absolutely incredible."
"The Java Mastery section is extremely detailed. Being able to visualize how the JVM handles memory, garbage collection, and the inner workings of ConcurrentHashMap was a game-changer."
120+ Visual Topics Covered in Deep Detail
Browse our complete pattern-based syllabus. Click the categories below to reveal our visual maps and problem lists.
Arrays & Strings
- check_circle Array Rotation & Offsets
- check_circle String Sliding Window
- check_circle Subarray Sum queries
Linked Lists
- check_circle In-place List Reversal
- check_circle Fast & Slow Pointers cycle
- check_circle Merging K sorted lists
Stacks & Queues
- check_circle Min Stack design
- check_circle Sliding Window Maximum
- check_circle Circular Queue simulation
Why Developers Choose AlgoSteps Visual Labs
Traditional Prep Sites
- closeDry Static Reading: Reading dry paragraphs of code and trying to imagine how variables change in memory.
- closeUnstructured Grind: Grinding random coding problems without understanding underlying patterns.
- closeDry Explanations: Complex system designs explained through plain text, skipping failure simulations.
AlgoSteps Visual Interactive Labs
- doneInteractive Tracing: Watch variables, indices, and pointers swap dynamically on interactive code sidebars.
- donePattern-Based Journey: Solve any new question by mastering the 27 core coding patterns step-by-step.
- doneHigh-Fidelity Playgrounds: Trigger cluster crashes, test server eviction configurations, and see algorithms solve issues live.
Earn Your Verified Certification
Complete our coding modules and design challenges to earn a secure, verifiable Certificate of Achievement. Share it directly on LinkedIn or display it on your resume to stand out in technical recruiter pipelines.
- workspace_premium Secure verifiable certification ID
- share 1-click sharing to LinkedIn Profiles
- military_tech Recognized credential for tech interviews
Practice Library
Coding Problems
500+ curated DSA questions with interactive execution canvas.
System Design
Master large-scale system design, microservices, and databases.
Object Oriented Design
Ace OOD, UML class diagrams, and design pattern interviews.
Interactive Visualizers
Visualize data structures, sorting, and graph traversals in 2D/3D.
Java Mastery lock
Deep-dive into JVM memory, HashMap collisions, and concurrency.
Python Mastery lock
Deep-dive into Python memory, the GIL, and generator execution.
AI Mastery lock
Visualize neural networks, RAG pipelines, and LLM decoding.
SQL Mastery lock
Master joins, execution order, B-Tree indexes, and transactions.
React Mastery lock
Deep-dive into Fiber reconciliation, hooks memory, and render flow.
Angular Mastery lock
Master change detection, dependency injection, and RxJS streams.
Git Mastery lock
Visualize commits, branches, merges, rebases, and conflict resolutions.
CSS Layouts Mastery lock
Interactive playgrounds for Flexbox, CSS Grid, and the Box Model.
JavaScript Mastery lock
Master the Event Loop, asynchronous JS, Promises, and prototype chains.
HTTP & API Mastery lock
Visualize request-response cycles, headers, and REST API endpoints.
CLI & Linux Mastery lock
Simulate a live virtual Linux file system and run terminal commands.
Web Security Mastery lock
Simulate OAuth 2.0 flows, SSL handshakes, and OWASP SQL injections.
12-Factor Microservices lock
Simulate cloud-native microservices, process scaling, configurations, and logs.
bolt FREE INTERACTIVE PLAYGROUND
Best Time to Buy and Sell Stock
Visualise the Best Time to Buy and Sell Stock algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying array data structure.
Climbing Stairs
Visualise the Climbing Stairs algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying array data structure.
Intersection of Two Linked Lists
Visualise the Intersection of Two Linked Lists algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying linked-list data structure.
Invert Binary Tree
Visualise the Invert Binary Tree algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
Linked List Cycle
Visualise the Linked List Cycle algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying linked-list data structure.
Lowest Common Ancestor of a Binary Search Tree
Visualise the Lowest Common Ancestor of a Binary Search Tree algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
Majority Element
Visualise the Majority Element algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying array data structure.
Maximum Depth of Binary Tree
Visualise the Maximum Depth of Binary Tree algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
Merge Two Sorted Lists
Visualise the Merge Two Sorted Lists algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying linked-list data structure.
Path Sum
Visualise the Path Sum algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
Reverse Linked List
Visualise the Reverse Linked List algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying linked-list data structure.
Single Number
Visualise the Single Number algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying array data structure.
Symmetric Tree
Visualise the Symmetric Tree algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
Two Sum
Visualise the Two Sum algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying array data structure.
Valid Anagram
Visualise the Valid Anagram algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying string data structure.
Valid Parentheses
Visualise the Valid Parentheses algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying string data structure.
science FREE INTERACTIVE SIMULATORS & LABS (OPEN ACCESS)
Engineering Manager Simulator
Step into the shoes of an EM. Handle team conflicts, project deadlines, and make critical leadership decisions.
LLM Tokenizer & Self-Attention
Interactive beginner & staff-level visualizer! Type custom text, watch BPE tokenization, inspect 3D vector embeddings, and explore 2D Q/K/V attention heatmaps.
RAG & Vector Search Simulator
Interactive RAG & Vector Search Simulator with document chunking sliders, 2D/3D vector similarity space, live prompt assembly diffs, and beginner/intermediate toggles.
AI Agent Thought Loop & Tool Calling Simulator
Interactive AI Agent Thought Loop & Tool Calling Simulator with glowing node-based ReAct flowchart, tool selection sandbox, custom prompt execution, and beginner/intermediate toggles.
Circular Array Modulo Pointer Simulator
Visualize how a circular array (ring buffer) pointer wrapping works dynamically using the modulo operator (index + 1) % size.
Parking Lot OOD Grid Allocator Simulator
Simulate parking lot object-oriented design and spot allocation strategies based on vehicle size constraints. Track billing and clock speed multipliers.
OOD Deck of Cards & Blackjack Simulator
Visualize standard deck model design (Encapsulation, Enums, Aggregation) and test it inside a complete interactive Blackjack game loop.
Cybersecurity Attack Simulator
Simulate SQL Injection, XSS, CSRF, and DDoS attacks. Learn how vulnerabilities are exploited and mitigated.
DNS Lookup Simulator
Trace a DNS query from the browser to Root, TLD, and Authoritative Name Servers step-by-step.
IP & CIDR Subnet Simulator
Visualize IP addressing, CIDR notation, and subnetting. Calculate subnet masks and host ranges interactively.
How the Internet Works
Watch the journey of a request: DNS resolution, 3-way TCP handshake, IP routing, and browser rendering.
OSI Model & Encapsulation
Visualize how data is encapsulated as it moves down the 7 layers, sniff packets on the wire, and watch decapsulation.
Hashing vs. Encryption Lab
Compare one-way hashing (MD5, SHA-256) with two-way symmetric (AES) and asymmetric (RSA) encryption.
Cron Job Simulator
Build and test cron expressions. Watch a live time-lapse simulation of scheduled tasks executing.
Semantic Versioning (SemVer)
Master SemVer rules, caret/tilde ranges, and version bumping through interactive scenarios and quizzes.
CSS Flexbox Playground
Interactive flex container with boxes that smoothly slide into position as you toggle alignment, wrapping, and sizing.
CSS Grid Builder
Drag-select cells on an interactive canvas to partition space and visually build custom two-dimensional grid layouts.
JSON Serialization Studio
Animate how JS objects are stringified and parsed, detailing rules for functions, undefined, and circular structures.
REST API Client Studio
Send GET, POST, PUT, and DELETE requests, watch the packet travel, and see the database update in real-time.
Web Storage Cabinet
Interactive cabinet comparing Cookies, LocalStorage, and SessionStorage lifespans, capacities, and network transmission.
Git Branching Lab
Interact with Git commits, HEAD, and branch pointers in a DAG graph. Simulate fast-forward and 3-way merges.
ATS Parser & Keyword Matcher
Live laser scanner simulation. Watch how an ATS parses keywords, flags passive phrases, and scores interview probability.
6-Sec Recruiter Eye-Tracking
Simulate human recruiter eye-tracking in the first 6 seconds using F-pattern and E-pattern heatmaps over different resume styles.
workspace_premium PREMIUM PRACTICE LIBRARY
lock Add Binary
Visualise the Add Binary algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying string data structure.
lock Add Digits
Visualise the Add Digits algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying array data structure.
lock Add Strings
Visualise the Add Strings algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying string data structure.
lock Arranging Coins
Visualise the Arranging Coins algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying array data structure.
lock Average of Levels in Binary Tree
Visualise the Average of Levels in Binary Tree algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
lock Backspace String Compare
Visualise the Backspace String Compare algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying string data structure.
lock Balanced Binary Tree
Visualise the Balanced Binary Tree algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
lock Binary Search
Visualise the Binary Search algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying array data structure.
lock Binary Tree Inorder Traversal
Visualise the Binary Tree Inorder Traversal algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
lock Binary Tree Paths
Visualise the Binary Tree Paths algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
lock Binary Tree Postorder Traversal
Visualise the Binary Tree Postorder Traversal algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
lock Binary Tree Preorder Traversal
Visualise the Binary Tree Preorder Traversal algorithm. Step through the execution line-by-line with real-time visual tracing of the underlying tree data structure.
Frequently Asked Questions
Got questions? We've got answers to help you start your algorithm mastery journey.
Yes, absolutely! By understanding data structures visually and tracing their state modifications step-by-step, you build an intuition for patterns rather than just memorizing code. This deep fundamental understanding allows you to tackle variations and unseen problems easily in real interviews.
No, we offer a completely free trial allowing you to view and interact with our selected, stunningly designed demo problems (like Two Sum, Reverse Linked List, and Merge Binary Trees) right out of the box. You can test our platform's smoothness and quality before making any commitments.
Standard tutorials show you finished code or slides. AlgoSteps offers interactive step-by-step simulations where you can see variable states updating in real time, line-by-line, and understand exactly when and how data moves. It's an active learning experience rather than a passive one.
AlgoSteps operates on a developer-friendly Freemium model! You get open access to 50 starter coding problems and 15 interactive simulators (including Networking, Git, CSS, and basic AI workflows) completely free. For advanced interview preparation, upgrading to Premium unlocks all 500+ advanced LeetCode problems, 500+ staff-level System Design, Network & DSA sandboxes, and full code execution!
AlgoSteps works directly in your modern web browser on both desktop and mobile devices. However, because our visualizer involves rich, responsive animations and canvas rendering, a desktop browser or tablet is highly recommended for the best experience. An active internet connection is required as simulations load dynamically.
All your progress, bookmarks, and custom problem configurations are securely synced to your user profile in the cloud via Firebase. When you sign in with your Google account, your history and progress are instantly restored across all your devices, allowing seamless continuation of your prep.
Yes, we support a modern, dark-by-default aesthetic with premium glows and glassmorphic panels for a stunning and immersive study experience. Our application is designed with high contrast and smooth transitions that are easy on the eyes during long preparation sessions.
We are constantly expanding our algorithm and data structure visualizer database to cover more advanced topics and real-world scenarios used in tech companies. If you'd like to request a specific data structure or algorithm, you can submit your feedback via our in-app feedback form, and we'll prioritize it for future releases!
Ready to Level Up Your Coding Prep?
Join thousands of engineers who have mastered data structures, algorithms, and system design visually. Get access to detailed step-by-line tracing, interactive quizzes, and visual roadmaps used by developers at top tech companies.